Bill entered the field of Internet routing research in 1989, while serving as the network architect and operations director for an international multiprotocol service-provision backbone network. In 1993 and 1994, Woodcock was one of the founders of Packet Clearing House, and has served in his current post as Executive Director since 1997. In that time, Woodcock has directly participated in the establishment of more than three hundred public Internet exchange points in Europe, Africa, Asia, and the Americas. He continues to serve on the boards of, and provide ongoing technical and policy advice to many of these institutions. In 1998, Woodcock and J.D. Falk's model spam regulation became the first anti-spam legislation in the world, California law 17538.4, and paved the way for other jurisdictions. Woodcock has successfully concluded telecommunications regulatory reform efforts in several African countries.

Woodcock has director roles in four companies in the areas of satellite communications, content distribution, and domain name service technology. In 2001 Woodcock co-authored (with Chuck Goolsbee) "Chuck & Woody's Fiendishly Difficult Mac-Mgrs Trivia Quiz" for the annual gathering of member of the Macintosh Managers mailing list in San Francisco for Macworld Expo. To date over 50% of the questions remain unanswered.[citation needed] For more than twenty years, together with Richard Ford and initially Brita Meng, he hosted the annual and inaptly named A/UX User's Group Dinner, in conjunction Mactivity and Macworld meetings.[citation needed]

Woodcock's published work includes many PCH white-papers, the 1993 McGraw-Hill book Networking the Macintosh, the report of the ANF AppleTalk Tunneling Architectures Working Group, which he chaired in 1993 and 1994, many articles in Network World, MacWorld, MacWEEK, Connections, and other networking journals and periodicals.[8] In addition, he was principal author of the Multicast DNS, IP Anycast, and Operator Requirements of Infrastructure Management Methods IETF drafts. In the early 1990s, he pioneered IGP and EGP-based topological load-balancing techniques using IP Anycast technology. Together with Mark Kosters he proposed at the 1996 Montreal IEPG that the root DNS servers be migrated to IP Anycast, and their work has provided the basis upon which root DNS servers have been deployed since the late 1990s.[9] In 2010 and 2011, with Rick Lamb, who had previously built the signing system that places DNSSEC cryptographic signatures on the DNS root zone, Woodcock built the first global-scale FIPS 140-2 Level 4 DNSSEC signing infrastructure, with locations in Singapore, Zurich, and San Jose.[10][11][12][13] In addition to protocol development work, Woodcock has developed networking products for Cisco, Agilent, and Farallon.